1. The system is expected to produce heavy rainfall and considerable flash, urban, and small stream flooding beginning Friday and continuing through the weekend along the central Gulf coast and spreading northeastward into the Southern Appalachians.

2. Tropical storm conditions are expected to begin Friday in areas near and well to the east of the center along portions of the central Gulf Coast from Intracoastal City, Louisiana, to the Alabama/Florida border, including New Orleans.

CHANGES WITH THIS ADVISORY:

A Tropical Storm Warning has been issued for the Gulf Coast from Intracoastal City, Louisiana, to the Alabama/Florida border, including Lake Pontchartrain, Lake Maurepas, and Metropolitan New Orleans.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Tropical Storm Warning is in effect for...
- Intracoastal City Louisiana to the Alabama/Florida border
- Lake Pontchartrain, Lake Maurepas, and Metropolitan New Orleans

A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within 36 hours. Interests elsewhere along the northern Gulf Coast should monitor the progress of this system.

RAINFALL: The potential tropical cyclone is expected to produce total rainfall of 3 to 6 inches with isolated amounts of 8 inches across the Yucatan Peninsula of Mexico. Rainfall totals of 4 to 8 inches with isolated maximum amounts of 12 inches are possible beginning Friday and continuing through the weekend from the Central Gulf coast northeastward into the Southern Appalachians. This will likely produce areas of flash, urban, and small stream flooding as well as minor to isolated moderate river flooding with new and renewed rises on already elevated rivers.

STORM SURGE: The combination of storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water could reach the following heights above ground somewhere in the indicated areas if the peak surge occurs at the time of high tide... Intracoastal City, LA to MS/AL Border...23 ft Vermilion Bay and Lake Borgne...23 ft Lake Pontchartrain and Lake Maurepas...12 ft MS/AL border to AL/FL border including Mobile Bay...13 ft Cameron, LA to Intracoastal City, LA...12 ft.

Surge-related flooding depends on the relative timing of the surge and the tidal cycle, and can vary greatly over short distances. For information specific to your area, please see products issued by your local National Weather Service forecast office.

WIND: Tropical storm conditions are expected to first reach the coast within the warning area on Friday, making outside preparations difficult or dangerous.

TORNADOES: The threat for a couple tornadoes should begin Friday afternoon across coastal Louisiana. This threat should expand northward across southern portions of Louisiana and Mississippi, and southwest Alabama on Saturday.

At 400 PM CDT (2100 UTC), the disturbance was centered near latitude 22.9 North, longitude 92.4 West. The system is moving toward the north near 9 mph (15 km/h) and this motion with some increase in forward speed is expected for the next day or so. On the forecast track, the system will approach the northcentral Gulf Coast late Friday or early Saturday. A northeastward motion across the southeastern United States is likely after landfall.

Maximum sustained winds are near 30 mph (45 km/h) with higher gusts. Some strengthening is forecast tonight and Friday. A subtropical or tropical depression or storm is likely to form over the westcentral Gulf of Mexico tonight or early Friday. * Formation chance through 48 hours...high...90 percent. * Formation chance through 5 days...high...90 percent. The estimated minimum central pressure is 1008 mb (29.77 inches).

Visible satellite images show that the cloud pattern associated with the broad area of low pressure located over the southwestern Gulf of Mexico is gradually becoming better organized. Deep convection is beginning to form a broad curved band over the eastern portion of the system, similar to what one might see in a developing subtropical cyclone. Although the upper-level winds are not particularly favorable for development, with lots of westerly shear over the area, the global models do suggest tropical/subtropical cyclogenesis within the next 12 hours or so. Given the proximity of the disturbance to land, which requires tropical storm warnings at this time, advisories are being initiated on this system as a potential tropical cyclone.

Earlier scatterometer data suggested that the circulation was stillrather broad. An Air Force Hurricane Hunter plane is currentlyinvestigating the system and has not yet found a well-definedcenter. Maximum winds based on surface observations and thescatterometer pass are near 25 kt. Numerical intensity guidance donot indicate a great deal of strengthening before the systemreaches the coastline, and the official forecast is at the high endof the guidance.

Since the center is not that well-defined at this time, the initialmotion estimate, 360/8 is quite uncertain. The system is expectedto move northward into a weakness in the subtropical ridge for the next day or so and then, after landfall along the central Gulf Coast, turn toward the northeast on the northwest side of amid-level anticyclone near Florida. The official track forecast isclosest to the GFS and ECMWF predictions. It should be noted,however, that these models suggest some reformation of the centernear the Louisiana coast rather than just motion from the southwestGulf to the expected coastal landfall point.Given the current and anticipated structure of this system, users should not focus on the exact track of the center, as rainfall and wind hazards are likely to extend well east of the center and arrive well in advance of landfall.